The Toronto International Film Festival will slim down its lineup this year by about 20%, hoping to remove some of the bloat that lately has made the festival a comprehensive but dizzying affair.

But if the quantity of the films has decreased, the quality of the included filmmakers has not: new movies by Darren Aronofsky (genre tale “Mother!”), Alexander Payne (magical-realist class picture “Downsizing”) and Guillermo del Toro (creature-feature drama “The Shape of Water”) will all play the post-Labor Day gathering. So will films by Wim Wenders (romantic drama “Submergence”) and Stephen Frears (immigrant-themed royals tale “Victoria and Abdul”).

The festival also will showcase a number of movies from prominent actors-turned-directors, organizers announced Tuesday. Among them are George Clooney’s home-invasion race-critique “Suburbicon” featuring Matt Damon (he does double duty with “Downsizing”); Angelina Jolie’s fact-based Khmer Rouge drama “First They Killed My Father,” a Cambodian production rooted in native culture; Greta Gerwig’s California comedy “Lady Bird” starring Saoirse Ronan as the title character; and Andy Serkis’ “Breathe,” about the real-life polio activist Robin Cavendish, played by Andrew Garfield.

Organizers this year are reacting to a view in recent years that Toronto can be overwhelming for participants and yield diminishing returns for studios; executives annually scramble to lobby for the best slots and worry their movies will be overshadowed by competitors’ titles.

“We still want to make sure we have a wide range, but we also want to make sure each film can stand out,” festival director Cameron Bailey told The Times in explaining the shift, which will lop off dozens of titles from the 300-plus of past years. “And as programmers we wanted to invite films we really fell in love with.”

When the festival kicks off Sept. 7, it will mark an unofficial start to Hollywood’s awards season. Nearly all the major premieres are looking to Toronto to jump-start a commercial release and generate early awards buzz.

Jolie and Serkis’ titles will not be the only real-life stories given pride of place. TIFF will also screen David Gordon Green’s Boston Marathon story “Stronger” starring Jake Gyllenhaal, and “Kings,” a drama about the 1992 Los Angeles riots from “Mustang” director Deniz Gamze Ergüven. Both deal with class — particularly the underclass — a topic that has been running through prestige films a lot recently, as it did at Cannes this year.

"The Current War," Alfonso Gomez-Rejon's exploration of the early battle over electricity with Benedict Cumberbatch as Thomas Edison and Michael Shannon as George Westinghouse, will also be on the docket. (Toronto announces its movies in stages, and further titles will be announced in the coming weeks.)

Feminist issues will be heavily featured at Toronto, via Jonathan Dayton and Valerie Faris’ “Battle of the Sexes,” about the run-up to the famous Billie Jean King-Bobby Riggs exhibition match, with Emma Stone as the tennis pioneer; “Mary Shelley,” Haifaa Al Mansour’s look at the personal and creative life of the great English writer starring Elle Fanning in the title role; and Susanna White’s “Woman Walks Ahead,” in which Jessica Chastain stars as Catherine Weldon, Sitting Bull’s chief advisor.

“Woman Walks Ahead” is among the titles that will make its world premiere at Toronto; so will “Stronger, “Mary Shelley,” “Kings” and “Breathe.” “Mother” and “Suburbicon” appear to be headed to the Venice Film Festival shortly before Toronto and “Father,” “Shape” and “Downsizing” will likely be in Telluride.

In a prolific filmmaking burst, the Argentinean-Chilean director Sebastián Lelio (“Gloria”) will bring two films to TIFF, both in a feminist vein: the lesbian romance “Disobedience” (a fall festival debut), and the trans drama “A Fantastic Woman,” which premiered in Berlin.

And cue the “Dunkirk” trend pieces: World War II movies seem to be in vogue again. Playing the festival will be “The Catcher Was a Spy,” Ben Lewin’s World War II baseball-player movie starring Paul Rudd; and Joe Wright’s “Darkest Hour,” in which Gary Oldman stars as an early-tenure Winston Churchill as the Hitler threat mounts.

Fact-based movies are hardly all serious look-backs, though. The prize for sheer outlandishness may go to Angela Robinson’s “Professor Marston & the Wonder Women,” with Luke Evans as the Harvard professor instrumental in the creation of both the polygraph and the Wonder Woman character.

The reduction in the lineup follows a change Toronto leaders made several years ago in which they began relegating movies that played the Telluride either to a smaller venue or a slot after the high-profile first weekend.

A number of studios have since effectively mined that strategy — in the last two years “Spotlight” and “Moonlight” each premiered later in Toronto after going to Telluride first and wound up winning the best picture Oscar.

“It's a little like sports,” Bailey said of how those wins have changed distributors' thinking. “Studio people can be superstitious and want the slots that have worked before.